Capping C02 emissions costs 18 cents per person per day

A new report by CBO says cap-and-trade will cost 18 cents per person per day.

And a big hand slap for Nat Keohane (of Environmental Defense Fund) for saying the cost was just a dime a day.

Yeah, I take such estimates lightly and tack on a lot of uncertainty. But CBO isn't biased.

Can someone explain to me why this is controversial?

Update: One big thing getting in the way of climate change legislation is deciding who gets to count all the carbon, particularly the offset part, which will be complicated. It's a conflict between two agencies that love each other dearly: USDA and EPA. Conflicts and a culture of distrust between these agencies go way back. On some level I think it's superficial stuff. Farmers don't know or like the EPA but do know and at least feel comfortable with their local FSA guys. Anyway, it's funny how agriculture always gets in the way on policy matters much bigger than itself, everything from trade agreements to climate change.